Two internal friction peaks which had been discovered in the pure metal at increasingly low temperatures were suggested to be different occurrences of the familiar Bordoni peak. The higher-temperature peak was attributed to the impurity-assisted nucleation of thermal kink pairs. The lower-temperature peak marked the onset of a new nucleation mechanism in which the geometrical kinks (anti-kinks) rearranged themselves into superkink-antikink pairs in order to overcome the Schottky barriers.

F.Marchesoni: Journal of Applied Physics, 1996, 80[1], 591-3